This invention relates generally to apparatus and methods for packaging food products, and more specifically, to improved equipment and methods for filling cylindrically shaped food casings for loaf style meat and sausage products.
In the manufacture of meat and sausage products, it is customary to prepare, for example, a meat emulsion from comminuted meat together with fillers, seasonings, spices, etc. A tubular food casing, such as nonedible cellulose, is loaded onto the stuffing horn of a filling machine and stuffed with the meat emulsion. For sausage products like bologna, salami, and the like, the meat emulsion is introduced into large, heavy walled fibrous type casings and formed into round shaped chubs or lengthy individual sausage sticks.
In contrast to rounded/circular shaped sausage products, U.S. Pat. No. 4,434,528 to Niedecker discloses square shaped products, such as hamloaf, turkeyloaf, etc., where the final product has essentially a rectangular or "D" shaped cross-sectional configuration resembling a slice of bread. Niedecker's methods begin with preparation of slack filled casing containing the desired final quantity of meat which is less than the casings volumetric capacity. The partially filled, rounded sausage is placed in a metal mold and compressed into a rectangularly shaped product.
More specifically, in preparing partially filled products according to Niedecker's method, a first length of casing is filled to capacity with the desired final volume of meat. A device for gathering casing and applying a closing clip is actuated. But, before being fully closed the first length of filled casing is compressed between a pair of mechanical jaws. The pressure applied is sufficient to compress the filled portion and simultaneously withdraw the product from the horn downstream in the filling direction causing residual unfilled casing on the filling horn to be drawn through the partially closed clip.
In the process, sausage meat is displaced upstream into the unfilled casing as the casing is drawn through to provide a slack filled product.
Thus, the methods of U.S. Pat. No. 4,434,528 are dependent on the direct application of substantial force through direct compression of a filled casing. In the process of displacing meat emulsion upstream unfilled casing withdrawn from the stuffing horn must be threaded through a partially closed chub clip. Unless the unfilled casing readily threads through the clip with pressure applied by the mechanical jaws there is an increased statistical risk of casing rupture occurring. This means potentially costly down time for cleanup, lost meat emulsion in the work area, lost production and wasted casings. Accordingly, it would be desirable to have a more reliable method and apparatus for preparing partially filled food casings which offer a lower risk profile for casing rupture.